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Wet sand and buff powder coating

My shop is powder coating 120 cast aluminum wheels, 90% gloss black. on occasion, a wheel comes out with noticeable orange peel. while we're working on eradicating the peel from the process, was wondering if its possible to wet sand the cured powder and polish back to a gloss?

Murray Jansen
powder coater - La Habra, California, USA
2007

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2007

Dear MURRAY
Regarding eradicating orange peels from process,please check following points.
1)Powder particle size should be in the range of 30 to 65 microns.Too fine or too coarse particle can cause the problem.Also remember deposition efficiency tend to fall beyond average particle size 40 microns.
2)Warming up of powder too slow or too fast in curing oven can cause the problem.Also insufficient curing can cause orange peeling.So please check heat distribution/hot air flow inside oven.Calibrate the oven half yearly.
3) Hope you are maintaining application parameters(fluidization air 0.8 to 1.2 kg/sq.cm, Atomization/booster air pressure 0.5 kg/sq.cm. Powder output 300 to 400 gms/min.) as per your article size.
4)Wet sand and polishing may be successful but in localized defective area.It will require high grade buffing wheels(fine levels),high quality pastes,and of course SKILL.
Orange peel defect has been accepted as an effect to certain extent,by industry.
Hope above matter will help you.
All the best.
Regards,

SATYAJIT VASANT PANDIT
- PUNE , MAHARASHTRA, INDIA